<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="dist/vue.js"></script>
    <style>
        .box{
            width: 100px;
            height: 100px;
            background-color: #f66;
        }
    </style>
</head>
<body>
    <div id="app">
        <div class="box" @click="boxfn">
            <button @click.stop="btnfn">btn</button>
        </div>

        <div class="box" @click.self="boxfn">
            <button @click="btnfn">btn</button>
        </div>
        <a v-on:click.once="doThis">lmx learning</a>
    </div>
</body>
<script>
    const app = new Vue({
        el: '#app',
        methods:{
            boxfn() {
                console.log('box');
            },
            btnfn() {
                console.log('btn');
            },
            doThis() {
                console.log('dothis')
            }
        }
    });
</script>
</html>